8 BOREAM Model concentrations for tracers in E0802 in Yasmeen et al. 2012NameBOREAM (ppt)8-Hydroxypinonic acid2910-Hydroxy pinonic acid210*Diaterpenylic acid53Norpinic acid11Terpenylic acid0.003**Diaterpenylic acid acetate< 0.001**MBTCA (conventional chem.)< 0.001MBTCA (pinonic acid direct pathway, Müller et al. 2012)2.8M172 (keto-diol)1298*A direct, but mechanistically unresolved formation of 2% of 10-hydroxypinonic acid from CI-1 was added in BOREAM, together with 10% pinalic acid and 6% pinic acid, based on Yu et al (1999). This production is not included in this value, which represents all explicit resolved pathways in the current mechanism.** A newly proposed pathway for ester formation from an alkoxy radical could potentially lead to several 10s of ppt of terpenylic acid and diaterpenylic acid acetate from pinonic acid. A similar pathway might perhaps be present in the pinonaldehyde mechanism, although there it would need to compete against a fast 1,5-H.shift

15 M172 product (dinorpinic acid)Difficult to find conventional pathway, as removal of a methyl group normally leads to replacement by an oxygenated group (H-shifts for alkyl radicals are unlikely)Other product with nearly identical mass, but 9 carbons is present in high yield